The present invention relates to sensing stellar objects such as the position of the sun and of stars for purposes attitude control of a space vehicle.
In order to determine attitude and orientation of a satellite in outer space optical detectors have been suggested which acquire so to speak the position of the sun and/or of particular bright stars. Corresponding to the position data thus acquired the satellite or space vehicle will be controlled with regard to its orientation and attitude. It has to be observed however, that f.ex. in the case of imaging the sun a disk, so to speak, is reproduced having a considerable larger diameter than a point like image of even the brightest star. These differences in image size of disk and point are to be understood in relation to the diameter or other representative dimension of a detector element. In view of these differences one needs in fact different and actually different types of electronic processing and evaluation circuits for determining the position of the sun and for determinging the position of any star. This problem is for example described in "Development Studies for a Polaris Sensor", SIRA Institute LTd. of June 1979, and in "Technical Description Sun Sensor" MBB/Erno of Nov. 28, 1983.